In one type of book binding, the binding includes a hard cover having a front side, a back side, and a backbone bridging the front and back sides. When the binding is in a closed position, the front and back sides are positioned generally parallel to one another and the backbone extends generally perpendicular to the front and back sides. The binding further includes a plurality of circular wire elements which, when the binding is in the closed position, may be either fully concealed or partially concealed by the hard cover.
In a binding with fully concealed wire elements, the inner surface of the hard cover is lined with paperboard. The paperboard substantially covers the inner surfaces of the front side, the back side, and the backbone of the hard cover, and the paperboard is adhered to the inner surfaces of the front and back sides by means such as glue. The paperboard is not adhered to the inner surface of the backbone, but rather remains separated therefrom by a small gap, so that the wire elements may be attached to the hard cover using the strip of paperboard located adjacent the backbone. More specifically, each circular wire element passes through an associated pair of adjacent apertures in the strip of paperboard such that an arc-like section of the wire element is positioned within the small gap between the paperboard and the backbone. The wire elements are "fully concealed" by the hard cover because they are located entirely within the interior thereof. The wire elements do not pass from the interior to the exterior of the hard cover.
In a binding with semi-concealed wire elements, the paperboard is adhered to the inner surfaces of the front side, back side, and the backbone so that no small gap exists between the paperboard and the backbone. Each wire element is attached to the hard cover by passing the wire element through an associated pair of adjacent apertures in the backbone itself such that an arc-like section of the wire element is located outside the hard cover adjacent the outer surface of the backbone.
In comparing the foregoing two bindings, an advantage of the binding with fully-concealed wire elements is that it permits writing or labels to be placed on the backbone without interference from the wire elements. Another advantage of the binding with fully-concealed wire elements is that it has a nicer appearance than the binding with semi-concealed wire elements because the wire elements in the former binding are hidden from view when the binding is in the closed position. The binding with semi-concealed wire elements, however, has the advantage that it is less expensive to manufacture than the binding with fully-concealed wire elements.
Accordingly, a need exists for a book binding which utilizes the advantages of both the foregoing binding with fully-concealed wire elements and the foregoing binding with semi-concealed wire elements.